This acquisition is for laboratory support for an NIDR study which is analyzing the clinical and medical conditions and selected immunological, behavioral, and other potential determinants of oral and systemic disease collected from a cohort of HIV-positive military personnel from 1987 to 1994 by the Walter Reed Army Institute of Research. The NIDR participated in this protocol to study the natural history of oral consequences of HIV infection. More than 800 subjects were enrolled in the oral health component from 1989 to 1994 and returned every six months for re-evaluation of their oral health status and for other tests and procedures. The purpose of the project is to assess the salivary HIV and salivary antiviral defense mechanisms in the saliva and serum of the study participants and relate these factors to the occurrence and progression of oral and systemic manifestations of HIV. The contract will support the NIDR study by undertaking the required laboratory assessments and the development of laboratory assay procedures to handle some special features of this particular research study, such as the large volume of samples and the need for procedures to conserve volume of specimen as much as possible.